Pump



.J. DICKS ON Dec. 2, 1958 PUMP 2 Sheets-Shea t 1 Filed June 22, 1954 Dec. 2, 1958 KsoN 2,862,655

PUMP Filed June 22, 1954 Sheets-Sheet 2 lNVENTORS (3/5522 Dbfsbz;

ATTORNEY I PUMP John Dickson, Huntington Woods, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 22, 1954, Serial No. 438,558v

6 Claims. (Cl. 230141) This invention relates generally to a rotary fluid pump or blower and more particularly to a combined blower and pump of the rotary type, particularly adapted among other uses for supplying scavenging air to a two-cycle vehicular engine while at the same time serving as a source of suction for the operation of suction actuated vehicular accessories and devices.

An object of this invention is to provide an improved two-chamber pump or blower capable of pumping two fluids simultaneously.

A further object of this invention is to provide such an improved two-chamber pump withan improved lubricating means. 7

Still another and more specific object of this invention is to provide a combined blower and vacuum pump of the lobed impeller type with an improved means to supply lubricant to the journals of the blower and to lubricate and seal the pump.

These and other objects of the invention are accomplished in a preferred embodiment of the invention by providing a blower having a pair of lobed impellers with shafts which are extended to drive a second pair of lobed impellers in a secondary vacuum pump housing mounted on the end of a main blower housing. The second set of impellers are splined on the shaft extensions to rotate in aligned relation with the blower impellers and Y ends of the shafts 28 and are connected to a pair of serve as a secondary fluid pump. Lubricant supplied to v the shaft journal bearings between the two pumps is delivered to both sides of the vacuum pump by permitting it to flow along the shaft into the secondary pump housing and through the splined connections between the impellers and the shafts. The lubricant is then carried radially outwardly of the secondary impellers by the rotation thereof to provide an effective lubricating seal between the mating surfaces of the secondary impellers and the secondary housing.

The above mentioned objects of the invention will be more thoroughly understood from the following description of a preferred embodiment thereof in which reference is made to the attached drawings, in which:

Figure 1 is a sectional view of a combined blower and vacuum pump constructed in accordance with my invention taken substantially on the line 11 of Figure 2.

Figure 2 is an end view of the vacuum pump with portions broken away and in section along the line 2--2 of Figure 1.

Referring more particularly to the drawings the combined pump includes a main casing 10 closed at each end by the end plates 12 and 14 to form the main pump or blower chamber 8 and having intake and discharge openings 9 on opposite sides thereof. The end plates are secured to the casing member 10 by a plurality of dowels and stud bolts as indicated at 15, 16, 17, 18 and 19 and are provided with transverse bolt holes as indicated at 20, 21 and 22, 23, respectively, forsecuring the combined unit to a mounting device, not shown, such as the cylinder block of a two-cycle vehicular engine. Two

hollow lobed rotors or impellers 24 and 26 are rigidly 2,862,655 Patented Dec. 2, 19 58.

mounted on spaced parallel shafts 28 and 30 which are rotatably journaled in the end plates 12 and 14 as indicated at 12, 12" and 14', 14", respectively. The up- 1 per rotor. is adapted to be rotatively driven by the vehicular engine through a drive shaft 40 which is connected through a resilient coupling 42 to an upper rotor timing gear 29 secured to the drive end of the shaft 28. The upper gear 29 in turn drives a lower rotor timing drive gear 31 mounted on the shaft 30 to rotate the lower rotor in phased relation to the upper rotator. The lower gear 31 is provided with a suitable drive coupling for a governor or tachometer as indicated at 44. The shaft 40, the resilient coupling 42, and the gears 29 and 31 are enclosed by a cover plate 46 which is retained in sealing relation with a gasket 48 on the end plate 12 by the bolts and dowels 15 and 17.

The opposite ends of the shafts 28 and 30 are extended to project within a'secondary pump or blower chamber 58 aligned with the blower chamber 8 and formed of a cover member 60 for the end plate 14 and a secondary pump housing member 62, both of which are secured to the end plate 14 by the bolts and dowels which secure the end plate to the main casing member 10. It will be noted that the end member 14 and the cover member 60 combine to form a partition wall between the blower chamber 8 andthe pump chamber 58. The extended secondary lobed impellers 64 and 66 by means of splined connections and 67, respectively. The splined connections 65 and 67 may either be provided with sufiicient clearance between the lands of the connection, as indicated at 68, 0r by the elimination of one or more of the splined teeth from the shaft or impeller, as indicated at 69, to permit the passage of a lubricant such as oil longitudinally of the shaft within the secondary pump, as more fully set forth below. The secondary pumping chamber 58 is provided with a suction intake at 72 which is connectable to a vacuum tank, not shown, and suction actuated vehicular accessories and devices, also not theadjacent engine,-not shown, through conduits 50 and 52. The conduits 50 and 52 are connected to passages 54 and 56 formed in the end plates 12 and 14, respectively, which communicate with the shaft journals through ports indicated at 54, 54", and 56', 56", respectively.

Since the spacing of the shafts and the phasing of the timing gears is such as to permit the lobes of the upper and lower rotors to revolve with close tolerances between.

the lobes of the rotors and the inner surface of the blower casing, the lobes of the upper and lower rotors of the blower do not touch at any time and lubrication between thesetwo members is not required. Oil seals 32, 34, 36'

and are provided in the blower end plates 12 and '14 to prevent the oil used for lubricating the rotor vshaft bearings from entering the blower compartment. This is.

essential when the blower is used for air scavenging .pur: poses in a two-cycle compression ignition engine. The

seals also serve to prevent air leakage from the blower:

along the rotor shafts.

54, 54", and 56, 56" towards the oil seals is returned tochambers 12 and 14' formed in the space between the end plates .12 and 14 and the cover members 46 and 60, respectively, ,by the passages76', 76", and 78', 78f. Oil,

moving longitudinally of the shafts toward the Oil moving longitudinally of the shafts from the ports:

gears drains into the chamber 12 while oil moving longitudinally'ofthe'shafts 28and 30 awayfrom the seals 36 and 38 is continuously metered into the secondary pump through the cover plate 66. Drains 80 and 82 provided in'the-eri'd plates returnthe oilcollectedtin the chambers 12-and 14 to a lubricant sumpynot shown, such as'the engine crankcase. 'T'he'drain "80 is so located that "the oil collected-in the chamber 12' will'submerge the lower teeth of the gear 31 for the purpose of lubricating the meshing-surfaces of the teeth of both timing gears with the oil elevatedby the lower gear teeth.

"The oil continuously metered into the secondary pump serves to provide a lubricating seal between the mating surfaces of thesecondary impellers and the secondary housing. Such an oil seal in the secondary pump is necessary fortheefiective generation of a suitable vacuum fOrJoperating thevarious vehicular accessories. To insure "the effectiveness of this sea'l the 'oil entering the secondary pump is deliveredtoboth sides or endsurfaces of the impellers 64- and 66; the clearances between the secondary-impellers and the cover plate 60 are such that a portion of the oil initially delivered to the left side of the :impellers, .as viewed in .Figure 1, is caused to pass through the clearances .68 .or the openings 69 provided betweenthe mating splines of theshafts and the impellers to atheopposite .end surfaces on the right side of the impellers thereby balancing the sealing lubricant supplied to .both end surfaces of the impellers. The oil delivered to the and surfaces of theiimpellers is then directed outwardlyfrom zones adjacent'the mountings of the impellers on their respective shafts by the radial components of .the centrifugal forces set up by the rotation of'the impellers. It will thus be seen that the invention provides an effective means for-metering a balanced and continuous lubricating and sealing .film between the surfaces of impellers and the vacuum pumping chamber. The metering .of the fluid to the vacuum pump by the journal portions of the partition and shafts prevents undesirable pumping of the lubricant which would bleed from other portions'of the engine lubricating system by the vacuum pump. As indicatedabove, the lubricating oil supplied to the vacuum pump is preferably discharged to the engine crankcase along with the limited amounts of air withdrawn by the pump.

In view of the above description, it will be seen that a combined two-chamber pump .of an improved and compact design is achieved by which the several objects of the invention and other advantageous results are attained.

.As .many changes could .bemade in the above constructions without departing from the scope of the invention, itis.intendedthatah matter contained in the above description orwshown in the accompanying drawings shall be interpreted asQillustrative and not in a limiting sense withrespect to the appended claims.

I claim:

11A combined scavenging air blower and a vacuum pump suchas for supplying supercharging air to a vehicular engine and for supplying operating vacuum for vehicular accessories comprising a housing having a blower chamber and a vacuum pump chamber in axial alignment and separated by a partition wall, each of said chambers having a fluid intake port and a fluid discharge port, a pairof shaft membersjournaled in said partition and :extending into .said chambers, means for rotatably driving said shafts in phased relation to each other, cooperating impellersmounted :on each of said shafts within .eachof saidchambers andadapted to deliver fluid from said intake ports to said discharge ports upon rotation of saidshaftsby saiddriving means, a passage in said partition for supplying lubricant to the journal portions of saidtpartition, vsaid journal ,portions and the journaled surfaces of-said shafts constituting means for continously metering lubricant .to the adjacent end of said vacuum pump chamber adjacent the mounting of said impellers onsai'cl shafts, and passage means associated with the shaft .moun'tingof each of-said impellers for supplying 4 portions of the metered lubricant to the opposite ends of said impellers whereby lubricant is evenly centrifuged radially outwardly of both end surfaces of said impellers to provide an effective seal between said impellers and said housing.

2. A combined blower and vacuum pump as defined in claim 1 and including sealing means carried by said partition and embracing said shaft intermediate said passages and said blower chamber to prevent the passage of lubricant into said blower pumping chamber and to prevent the passage of pressurizedfluid from said blower chamber to said vacuum chamber through said journal portions.

3. In a combined blo-Wer'and vacuum pump asdefined in claim 1, the mounting of the impellers on said shafts within said vacuumpumping chamber comprising splined connections defining passages permitting the passage of portions of the metered lubricant longitudinally of said shaft to the opposite endsof said impellers.

4. A combined blower and vacuum pump comprising, in combination, a firsthousingmember havinga blower chamber therein,'a secondary housing member mounted on one end of said first housing member and defining a vacuum pumping chamber therebetween in axial alignment with said blower chamber, each of said chambers having an intake port and a discharge port, a pair of shafts journaled in said first housing member and extending through said blower chamber and into said vacuum pump chamber, co-operating impellers mounted-on each of 'said shafts within said blower chamber, secondary cooperating impellers mounted on said shaft extensions Within said vacuum chamber, means for rotatably driving said 'shaftsto maintain said impellers in phased relation to each other to .thereby compressibly deliver a gaseous fluid between the intake to discharge ports of said blower chamber and to generate a vacuum at the intake portof said vacuum chamber, passages in said first housing member for supplying lubricant to'the journal portions thereof, sealing means carried'by said firsthousing member and embracing said shaft intermediate said lubricant passages and said blower chamber toprevent the passage of lubricant into said blower pumping chamber, said sealing means being adapted to prevent the passage of pressurized fluid from "said blower chamber to said vacuum chamber through the journal portions intermediate said chambers, said last-mentioned intermediate journal portions and the surfaces of said shafts journale'd therein constituting metering; means for delivering lubricant longitudinally of said shaft to said vacuum pumping chamber, and said secondary impellers and said'shafts defining passages therebetween for supplying equal portions of the lubricant supplied to said vacuum pumping chamber to the opposite ends of the secondary impellers adjacent their mountings on said shafts whereby the metered lubricant will be evently distributed on both sides of said impellers to provide an effective lubricant seal intermediate said impellers and said housing members.

5. In a vacuum pump, a housing having a vacuum pumping chamber therein, said chamber having an intake port and a discharge port, a shaft journaled in said housing and extending into said chamber, said shaft being conneetable to a rotatable driving device, an impeller mounted on said shaft Within said chamber and adapted upon rotation thereof with said shaft to deliver fluid from said intake port to said discharge port thereby generating a vacuum at said intake port, a passage in said housing for supplying lubricant to the shaft journal in said housing, said journal and the journaled surface of said shaft constituting a means for continuously metering lubricant longitudinally of said shaft to said vacuum pumping chamber adjacent the mounting of said impeller on'said shaft, the mounting of the impeller on said shaft comprising a splined connection and defining at least one passage therebetween, said passage being adapted to deliver aportion of the metered lubricant longitudinally of said shaft to the opposite endof' said impeller whereby lubricant is evenly distributed and carried radially outwardly of both end surfaces of said impeller to provide an effective seal between said impeller and said housing.

6. A combined scavenging air blower and a vacuum pump such as for supplying supercharging air to a vehicular engine and for supplying operating vacuum for vehicular accessories comprising a housing having a blower chamber and a vacuum pump chamber in axial alignment and separated by a partition wall, each of said chambers having a fluid intake port and a fluid discharge port, a shaft journaled in said partition and extending into said chambers, means for rotatably driving said shaft, an impeller mounted on said shaft within each of said chambers and co-operating with their respective chambers upon rotation of said shaft to compressibly deliver a gaseous fluid between the intake to discharge ports of said blower chamber and to generate a vacuum at the intake port of said vacuum chamber, a passage in said partition member for supplying lubricant to the journal portion thereof, sealing means carried by said partition-and embracing said shaft intermediate said lubricant passage and said blower chamber to prevent the passage of lubricant into said blower pumping chamber, said sealing means being adapted to prevent the passage of pressurized fluid from said blower chamber to said vacuum chamber, said journal portion and the surface of said shaft journaled in said partition constituting means for continuously metering lubricant to the adjacent end of said vacuum pump chamber adjacent the mounting of said impeller on said shaft, the mounting of the impeller on said shaft comprising a splined connection and defining at least one passage therebetween, said passage being adapted to deliver a portion of the metered lubricant longitudinally of said shaft to the opposite end of said impeller whereby lubricant is evenly distributed and carried radially outwardly of both end surfaces of said impeller to provide an effective seal between said impeller and said housing.

References Cited in the file of this patent UNITED STATES PATENTS 672,970 Westinghouse Apr. 30, 1901 1,119,972 Machlet Dec. 8, 1914 1,443,764 Smith Jan. 30, 1923 1,451,859 Balcker Apr. 17, 1923 1,694,783 Johnson et a1 Dec. 11, 1928 1,890,573 Dubrovin Dec. 13, 1932 1,913,633 Heil et al June 13, 1933 2,126,247 Eppers Aug. 9, 1938 2,126,279 Redfield et al Aug. 9, 1938 2,208,273 Karasick July 16, 1940 2,316,565 Collier Apr. 13, 1943 2,335,284 Kendrick Nov. 30, 1943 2,337,849 Dubrovin Dec. 28, 1943 2,626,570 Armington et al. Jan. 27, 1953 2,668,655 Bowering Feb. 9, 1954 2,721,026 Dills Qct 18, 1955 

